Is there anything cheaper than Stability AI API for image generation?

Stability AI API is about $2/1000 images per https://platform.stability.ai/pricing (Stable Diffusion v1.5, 512 by 512, 30 steps).

Dall-E is $18/1000 images per https://openai.com/pricing#language-models.

Midjourney's highest tier only offers 60 fast hours on GPU, so I'm not counting Midjourney as I'm looking for an API that gives a response < 5 seconds.